Article for correcting master sheets



Filed Ju1y 24, 195s QKUSD KtitHhNUt E. M. YUNKER ETAL ARTICLE FOR CORRECTING MASTER SHEETS Shets-Sheet 1 IN VEN TORS. Ellen M. Yunker Charles L. Yunker ATTORNEYS.

Oct. 23, 1956 s. M. YUNKER ETAL ARTICLE FOR CORRECTING MASTER SHEETS 2 Sheets-Sheet 2 Filed July 24, 1953 INVENTORS. Ellen M. Yunker Charles L. Yunker BY MI W ATTORNEYS.

United States Patent ARTICLE FOR CORRECTING MASTER SHEETS Ellen M. Yunlter and Charles L. Yunker, Columbus, Ohio Application July 24, 1953, Serial No. 370,022

6 Claims. (Cl. 101-1494) Our invention relates to an article for correcting master sheets. It has to do, more particularly, with an article and a process for correcting a master sheet of the type designed for insertion in a typewriter where the desired matter is typed thereon and subsequently used in duplicating copies of the matter typed thereon. It is especially applicable to that type of master used in the Ditto reproduction process although it is not limited thereto.

This type of master sheet embodies a relatively heavy sheet of treated paper which is superimposed upon and adhered to a sheet of carbon paper coated with a special ink. As is well known, this complete unit is inserted in the typewriter with the master forwardmost and the characters are struck thereon, with the result that the characers are embossed on the back of the master and are coated with the ink from the carbon paper. Then a number of copies can be produced by contact of the embossed back of the master with plain sheets of paper.

At present it is difficult, time-consuming, and messy to correct the master whenever a mistake is made thereon. It is necessary to remove the master and the associated carbon from the typewriter and scrape oif the ink at the erroneous embossed character or characters on the back of the master, using a razor blade or other sharp instrument. This is usually delayed until the complete master is typed so that all the mistakes can be corrected at once and, consequently, it is easy to overlook mistakes and easy to make correctionsin the wrong places. The ink from the carbon is messy and gets on the hands and clothes of the stenographer and, consequently, considerable time is not only consumed in making the corrections but also in the necessary frequent washing of the hands. The ink often gets on the clothes or other articles and damages them. The use of a razor blade or other sharp instrument is hazardous to the stenographer and often cuts or tears the master sheet so severely that it must be done over. It is difiicult to keep the lines even because the master must be removed from the typewriter for removal of the wrong characters and it is then diflicult to return it to its exact original position in the typewriter.

' The result of all of the above is a master which is not neat and will not give the desired neat reproductions. Also, because of the above disadvantages, it is difficult to get stenographers who are willing to make these masters.

It is the object of our invention to provide a simple correction card and process of using it for correcting master sheets of the type indicated whereby all the disadvantages of the present method mentioned above are eliminated.

In the accompanying drawings we have illustrated our correction card and the method of using it. In these drawings:

Figure 1 is a plan view of the card used in the correction of the master.

Figure 2 shows the master and the carbon in the typewriter.

Figure 3 is a similar view showing the master with an error typed thereon.

Figure 4 is a similar view showing the correction card between the master and the carbon for correction of the error while in the typewriter by the use of an eraser.

Figure 5 is a similar view but showing the master after erasure of the wrong character and the use of a new piece of carbon paper behind the master at the correction point.

Figure 6 is a similar view but showing the master after correction.

In Figure 2, we have illustrated the master sheet 10 and the carbon 11 associated with a typewriter roll 12. In Figure 3, we have illustrated the same members with the misspelled word wronr typed thereon. Obviously, it is desirable to correct the word to wrong. According to our method, this can be done immediately after making the error and while the master sheet 10 is still in the typewriter in association with the carbon 11.

To do this, it is merely necessary to employ our correction card 13 illustrated in Figures 1 and 4 and a simple eraser 14 illustrated in Figure 4. The correction card 13 is inserted between the carbon 11 and the master 10 as shown in Figure 4 and the wrong letter r is removed merely by rubbing with the medium-hard eraser 14, the master sheet, at the error, being forced back into contact with the card 13. The correction card 13 must be completely behind the error and a clean unused portion thereof must be behind the error. The erasing is done inthe exact manner as a regular typewriter erasure on regular paper. The eraser is rubbed over the error thoroughly. The reason the wrong letter can be removed so easily is that the surface of the card 13, which comes into contact with the inked character on the back of the master, is of absorbent material and is treated with a special composition which will be described in detail below. If merely an ordinary card or blotter were used, the ink would blot and smear. After correction, the correct letter g can be typed over the point where the wrong r was removed, as shown in Figure 6, but first a new piece of carbon 11a must be placed beneath the point where the letter was removed, as shown in Figure 5, so as to provide a new supply of ink for the newly-struck letter.

In producing the correction card 13, I prefer to use ordinary blotting paper. However, other absorbent sheet material might be used, for example, an absorbent cloth. The card 13 is preferably covered with a cover sheet 15 for keeping it clean and may be provided with perforated lines 16 to permit the use of sections thereof and subsequent removal of each section after use.

The blotter or other absorbent material is coated with a paste composition, according to our invention, which gives it the necessary characteristics to permit the correction of the master as indicated above. This composition must contain substances which cover up and absorb the ink being removed from the master, which hold the substances of the composition together and on the blotter, which will combine with the oils and waxes in the old ink on the master, which provide a new coating on the master that will be compatible with the new ink, and which will serve as a solvent for the waxes and oils of the ink to be removed. Examples of these substances are as follows:

The following ingredients cover up and absorb the old ink on the master: Calcium carbonate Zinc stearate Talc Fullers earth Zinc oxide Patented Oct. 23, 1956 The following substances combine with the oils and waxes of the old ink on the master:

Zinc stearate (also a cover up'ingredient) Carbonate of lead (also a cover up ingredient) Talc (also a cover up ingredient) The following substance makes a new coating on the master that will receive the new ink:

Sodium silicate (waterglass) The following ingredients serve as a solvent for the waxes and oils of the ink to be removed: Glycerin Glycols In each instance, it is preferred to use the first ingredient listed but the others listed can be substituted with success.

All the ingredients listed above are in powdered form except glycerin and its substitutes, and waterglass which are in liquid form. The dry ingredients are mixed well and then the-liquid glycerin or its substitutes is added, mixing to a paste. Then the liquid sodium silicate is stirred well into the paste. A thin coating of the resulting paste is then applied to the blotter.

We have found the following formula in actual practice to be most effective:

1 part calcium carbonate 1 part acacia 1 to 2 parts zinc stearate 1 part sodium silicate (waterglass) 1 part glycerin Other formulas we have used and found effective are:

Still other formulas that have been used by us and that we have found to work successfully are:

In each of these formulas the parts are by weight.

It will be noted that in each of these formulas, the sodium silicate, which recoats the master to receive the new ink, and the glycerin, or a substitute, which serves as a solvent for the waxes and oils in the ink to be removed, are used.

One of the gums is used in each instance as an adhesive to hold the ingredients together and on the blotter. Also, one of the cover up agents is used and one of the substances which combine with the oils and waxes of t the old ink in all formulas.

Various other advantages will be apparent.

Having thus described our invention, what we claim is:

1. A correction device in the form of a blotter which is impregnated with a composition of the following formula:

1 to 3 parts of a material selected from the group consisting of calcium carbonate, talc, fullers earth, and zinc oxide;

1 part of a material selected from the group consisting of acacia, gum arabic, and tragacanth gum;

1 to 3 parts of a material selected from the group consisting of zinc stearate and carbonate of lead;

1 part of sodium silicate;

1 part of glycerine.

2. A correction device in the form of a blotter which is impregnated with a composition of the following formula:

1 part calcium carbonate 1 part acacia 1 to 2 parts zinc stearate 1 part sodium silicate 1 part glycerin.

3. A correction device in the form of a blotter which is impregnated with a composition of the following formula:

1 part calcium carbonate 1 part acacia 3 parts zinc stearate 1 part sodium silicate 1 part glycerin 4. A correction device in the form of a blotter which is impregnated with a composition of the following formula:

2 parts calcium carbonate 1 part acacia 3 parts zinc stearate 1 part sodium silicate 1 part glycerin 5. A correction device in the form of a blotter which is impregnated with a composition of the following formula:

2 parts calcium carbonate 1 part acacia 1 part zinc stearate 1 part sodium silicate 1 part glycerin 6. A correction device in the form of a blotter which is impregnated with a composition of the following formula:

1 part tale 1 part acacia 2 parts zinc stearate 1 part sodium silicate 1 part glycerin References Cited in the tile of this patent UNITED STATES PATENTS 429,704 Solberg June 10, 1890 668,565 Randolph Feb. 19, 1901 852,191 McFadden Apr. 30, 1907 1,905,118 Nadell Apr. 25, 1933 2,163,934 Collins June 27, 1935 2,164,035 Jones June 27, 1939 2,387,643 Champion Oct. 23, 1945 2,525,063 Bowman Oct. 10, 1950 OTHER REFERENCES Ellis: Printing Inks. 1940, Reinhold Pub. Corp. Only pages 116, 248, 317, 333 and 349 cited. (Copy available in Division 17.) 

1. A CORRECTION DEVICE IN THE FORM OF A BLOTTER WHICH IS IMPREGNATED WITH A COMPOSITION OF THE FOLLOWING FORMULA: 1 TO 3 PARTS OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF CALCIUM CARBONATE, TALC, FULLER''S EARTH, AND ZINC OXIDE; 1 PART OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF ACACIA, GUM ARABIC, AND TRAGACANTH GUM; 1 TO 3 PARTS OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF ZINC STEARATE AND CARBONATE OF LEAD; 1 PART OF SODIUM SILICATE; 1 PART OF GLYCERINE. 